1. Field of the Invention
This invention relates to control devices having six degrees of freedom input to be operated by the human hand. More specifically, the present invention is a six degree of freedom trackball for use as an input device for controlling or manipulating graphic images such as are displayed by a computer or television display, a head mount display or any display capable of being viewed or perceived as being viewed by a human.
2. Description of the Prior Art
Although there are many hand manipulated trackballs for use as computer control devices taught in the prior art, none are structured similarly to the present invention, and none offer all of the advantages provided by the present invention due to the significant structural differences.
One prior art disclosure which is known to me and which is believed somewhat relevant is taught in U.S. Pat. No. 5,298,919 issued Mar. 29, 1994 to M. Chang. The Chang device is a six axis computer controller for manipulation of computer graphics, and is structured as a mouse type input device having a roller ball on the underside requiring travel of the input device and housing thereof along a surface for the manipulation of the underside ball for input of information pertaining to two axes of linear movement, which is typical of "mouse" type controllers. The Chang device includes a thumb wheel to mimic linear movement along a third axis. The Chang device also includes a second roller ball (trackball) exposed for manual rotation on the upper surface of the housing, and upper trackball is provided to allow the user to input information pertaining to rotation about the three mutually perpendicular or orthogonal axes conventionally referred to as yaw, pitch and roll.
Disadvantages which I believe exist in the Chang device, which I believe I have inventively overcome with the present invention, include the requirement that the trackball housing be moved along a surface in order to input linear moment information. This requirement of surface contacting travel prohibits the use of the Chang device as a completely hand held controller, and prohibits the Chang controller from being incorporated into a multi-purpose controller such as a hand held television remote controller or a conventional computer keyboard. Additionally, substantial physical space is required on a desk or table on which to propel a mouse type controller.
Another disadvantage of the Chang controller is that it is not believed to be intuitive, or in other words, the mouse roller ball on the underside of the housing which inputs linear moment information in some directions, is not capable of inputs in all linear directions, and thus the Chang device includes the thumb wheel on the side which is utilized to emulate, approximate or represent linear movement along the third axis. The manipulative hand movements required to move linearly utilizing pushing of the mouse for some directions, and the actuation of the thumb wheel for other directions is not intuitive and thus sometimes confusing and difficult for the user. Furthermore, a mouse type controller such as Chang's cannot provide the desirable aspect of automatic return-to-center along the linear axes, or in other words, with a mouse, the user must, in some cases, move the mouse back to center since there are no feasible arrangements for the use of return-to-center springs.
Another prior art disclosure which is known to me and which is believed somewhat relevant is taught in U.S. Pat. No. 5,237,311 issued Aug. 17, 1993 to N. C. Wislocki teaching a trackball and selection device. The Wislocki device includes a trackball protruding from a housing. The housing is hingidly supported on one side, and supported on a opposite side by compression springs. On the spring supported side is a selection switch activated with manual downward pushing of the housing or trackball. The Wislocki device is not a six degree of freedom controller or even a six axis controller, and does not teach or anticipate the structure and advantages of the present invention.
Therefore, there exists a need for further improvements in the field of 3D or six degree of freedom controllers for manipulating graphics such as on or through a computer and monitor or television screen or any display.